Hi John,

Not sure if this will help but it sounds like the problem is that the latch is only catching on the first stage of locking. You may find that it is just the rubber bump stops being out of position preventing the tailgate from closing far enough to engage the second stage of the latch. These are easy to adjust yourself, as long as you have the correct Torx driver bit. There is a bit of adjustment on the striker and latch assembly but you have to remove quite a bit of trim to get access to them. Its all in the workshop manual. If you haven't got a copy of this I would recommend you get one. It really does answer most of the questions that come up, it can just take a while to find the correct section - its 3,000 pages! Let me know if you need a copy and I will upload it to my server for you to download.

Here's the brief section on the tailgate bumpers...